Article winding device

ABSTRACT

A pair of resistance wires are wound onto a take-up member by rotating the take-up, providing twist prevention and tensioning on the trailing end of the wire and axially spacing the turns being wound. The twist prevention and tension is maintained on the trailing wire end by a weighted U-shaped member attached thereto. The spacing is achieved by supporting a hook-shaped member on one wire so that the wires pass on opposite sides of one of the legs of said hook-shaped member, the dimension of said leg being the desired pitch distance of the wire spacing plus the sum of the radii of the two wires.

United States Patent Mochizuki et al. Aug. 7, 1973 [54] ARTICLE WINDING DEVICE 195,883 l0/l8'77 Buzzell 242/147 R 2,363,205 11/1944 Smith 242/42 X [751 lhvehwrsnf z h g figz? 3,481,549 12/1969 Cullen et al. 57 11 x 9 9 Takarazuka, all of Japan I Primary Exammer-B1lly S. Taylor [73] Assignee: Okazaki Manufacturing Company, At[0rney-Le0nard S, Knox Kobe, Japan [22] Filed: Jan. 8, I970 57 ABSTRACT PP N03 71327 A pair of resistance wires are wound onto a take-up d d Application Data member by rotating the take-up, providing twist pre- [62] Division of Ser No 697 554 Dec 26 1967 Pat NO vention and tensioning on the trailing end of the wire 3 574 93L and axially spacing the turns being wound. The twist prevention and tension is maintained on the trailing 52 U.S. Cl. 242/7.1s 242/147 R wire ehd by a weighted u'shaped member atmhed 51 Int. Cl irolc 17/00 therem- The spacihg is achieved by shppmhhg hook- [58] Field of Search 242/147 R 1 42 Shaped member One Wire that the wires Pass 242l7'15 opposite sides of one of the legs of said hook-shaped member, the dimension of said leg being the desired [56] References Cited pitch distance of the wire spacing plus the sum of the UNITED STATES PATENTS of the 3,343,356 9/1967 McKinnon 242/147 R 3 Claims, 15 Drawing Figures PATENIEUMIB 11w 3.750.968

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ARTICLE WINDING DEVICE This is a division of application Ser. No. 697,554 filed Dec. 26, 1967, now U.S. Pat. No. 3,574,931.

This invention relates to the winding of helicallywound resistance-type temperature measuring devices having extremely accurate response and ruggedness.

Resistance type temperature measuring devices are based on the principle that the resistance of a conductor changes when subjected to variation in ambient temperature. For compactness, such devices are commonly utilized in a form wherein the conductor is coiled upon a dielectric support in order that the temperature sensed is that existing in a restricted zone. A typical device of this class is so designed as to carry a maximum current of 5 ma. and to change its resistance from about 100 ohms to 140 ohms when the ambient temperature changes from C. to 100 C. The completed device has an exterior diameter of about 3.0 mm. and a length of about 35 mm. exclusive of the terminal leads. The coil comprises platinum wire of 0.04 mm. diameter with the turns separated by 0.1 mm. and is embedded in glass. The invention also relates to novel steps in the fabrication of a device as described and the apparatus employed therein, whereby the extremely fine wire may be coiled on its support with uniform pitch and without twisting of the wire on its axis.

IN THESE DRAWINGS:

FIG. 1 shows prior practice in effecting a junction between a lead wire and the end of the wire forming the resistance element;

FIG. 2 is a longitudinal cross section through one end of the support to show the improved junction of the invention;

FIG. 3 shows one step in fabricating the junction of FIG. 2;

FIG. 4 shows a step subsequent to that of FIG. 3;

FIG. 5 shows the support and the length of wire prior to coiling of the latter;

FIG. 6 is an isometric view of apparatus utilized in winding the coil on its support;

FIG. 7 is a somewhat enlarged detail of an adjunct used in attaining uniform spacing between the turns of the coil;

FIG. 8 is an enlarged isometric detail of portions of FIG. 6;

FIG. 9 shows the coil completely wound and the looped end thereof anchored to the support;

FIG. 10 illustratesthe priorpractice ofanchoring the end of the coil;

FIG. 11 is a cross section in detail to show the .integration of the coil with its support before encapsulation;

FIGSI 12, 13 and 14=illustrate steps inencapsulating thecoil and supportyand FIG. 15 shows the completeddevice.

Broadly regarded the device of the invention comprises adielectric support upon which the resistance wire is wound, usuallyin a bi-filar configuration, the

beginning ends of the turnsbeingconnected to terminal leads located at one end of the support andtherremote end being anchored on a pin embedded in the support. The turns, including theend portionsthereof, are reliably united to the support by embedment therein. The assembly as thusconstitutediis encapsulated in a di-electric layer which virtually surrounds the turns of the coil and,=in the case where the dielectric is glass, fusion is resorted to in order to achieve a completely integrated structure.

In a further aspect the invention has relation to improvements in the winding apparatus whereby uniform spacing between the turns of the coil may be accomplished in a simple manner by an adjunct which is capable of being rapidly installed and adjusted for various spacings. Further the apparatus includes means to restrain the length of wire being coiled from twisting on its own axis.

Now adverting to the drawings there is shown, FIG. 1, a prior mode of splicing the fine wire 10 comprising the resistance coil to the comparatively heavier wires 11 forming the terminal leads of the device. In accordance with such prior practice wires 10 and 11 of each set are held side by side manually and the same are then spot-welded together. The attendant problems have been: (1) abnormally strained attention on the part of the operative to maintain the wires in proper relation pending welding, (2) the proportioning of the heat of welding in the case of wires of the magnitude involved is extremely difficult; if too great, the fine resistance wire will evaporate and, if insufficient, the larger diam eter wire absorbs heat to the detriment of the smaller and (3) there exists no practical way of determining whether the completed splice is capable of resisting mechanical shock and embrittlement incident upon heating and cooling.

In accordance with the invention securement of the beginning ends of the resistance wire to the terminal leads is achieved in a manner which avoids the several disadvantages just noted.

Thus, referring to FIGS. 2', 3 and 4 a section 15 of glass rod upon which the coil is to be wound is provided with a pair of terminal leads 16--16. For reasons which will become evident the section 15 is initially somewhat longer than its finished length. The leads 16-16 are offset at l7l7 in such manner that the ends l8l8 lie flush with the outer surface of the support. After this the ends 18 are grooved as at 21 for a short distance, in the example 1.5 mm., the transverse extent and shape of the groove being such as to receive the end of the finer wire 22 which is to constitute the coil, as indicated in FIG. 3. The position of the wire 22 within the groove is such that the walls 2626 thereof may be squeezed or rolled over to embrace the wire 22 (FIG. 4). .Even the burr raised on each side by the grooving cutter, when turned back may be sufficient to hold the finer wire adequately. The end result is that the wires 22-22 are gripped, as in a vise. At this juncture it is deemedpertinentto emphasize that, in typical devices, the resistance wire is on the order of 0.03 to0.07 .mm. (0.0018 to 00028 inch) in diameter and the terminal leads on the order of 0.3 .to 0.5 mm. (0.018 to 0.0l97

inch) in diameter. Finallythe wires 18 and 22 arepreferablyfurther secured by welding. In thiscasetheprior mechanical splicing serves tobring the two wires into .good heat-conductingrelation so thattheheat of weldiing isproperly.distributedand a reliable junction is attained.

Since, in theexample, the .coil of resistance wire is wound bi-ifilar the sub-assembly, following the steps described, will appearasin FIG. 5, with the return loop indicatedat 30.

The support 315 is now grippedatitsleftend in a chuck or collet 41 carried at one end of a spindle 42 rotatably supportedin standards 42 and 44 carried on a base plate 45. A handwheel 48 is keyed to the outer end of the shaft 42.

A carriage 51 has a threaded hole 52 engaged with a lead screw 53 journalled in the standards 43 and 44 and a third standard 55. A fixed guide rod 57, secured at its ends in the standards 44 and 55, is slidably received in a bore 58 in the carriage 51 to constrain the same to move in a straight path pursuant to rotation of the lead screw. Change gears 61 and 62 of any desired ratio translate. the rotational speed of the chuck 41 into a predetermined longitudinal speed of the carriage 51. As will be understood such ratio is determined jointly by the predetermined pitch of the turns of the coil and the speed of the spindle 42.

An outboard bracket (not shown) carries an idler sheave 65 over which a length of cord 66 is arranged to run. The depending end of the cord carries a weight 68 selected to apply appropriate tension to the wires 2222 as they are wound. Inasmuch as the wires 2222 are so fine and prone to damage if allowed to twist and kink, provision is made to obviate such behaviour. To this end a device 71 is interposed between the cord 66 and another piece of cord 69. This device comprises a piece of rigid wire 70 bent into horseshoe shape and having a weight 73 of sufficient size hung on the bight to maintain the cord 69 and hence the wires 2222 in a predetermined position, i.e. with the wires in a common plane essentially tangent to the surface of the support 15. The ends of the cords 66 and 69 are secured in any convenient manner to the legs of the horseshoe member 70.

To establish and maintain some predetermined spacing S (FIG. 7) of the turns of the wires 2222 an adjunct 74 as there shown is employed. This device comprises a piece of wire bent into the form of a loop 75 but interrupted at 76 in order that the same may be hung over one of the wires 22, e.g. the left-hand one. The diameter of the wire of the loop 75 is so selected that, when the loop is located in working position as shown the space S will be maintained as winding proceeds. A weight 78 having a hook 79 is suspended from the lower bight of the loop 75 to maintain this latter in its prescribed position. To insure greater accuracy the inside corner 81 of the loop may be squared off. It will be apparent that the spacing S will be the pitch less one wire diameter, and that different adjuncts 74 will be used whenever the dimension S and/or the gauge of the wire 22 is changed. If the adjunct is employed in a situation where two wires of different diameters are being wound then S will be the pitch less the sum of the radii of the two wires. Moreover, it will be understood that, where more than two wires are being wound, the portion of the device intermediate the wires will be in plural.

As previously noted the wires 2222, together with the device 74 are advanced to the left as the support is rotated. To this end the carriage 51 is provided with a rod 85 adjustably held in a socket 86' by a knurledhead screw 87. The left-hand end 89 of the rod 85 is bent to bear against the right-hand one of the wires 2222. It will be noted that the point at which the end 89 abuts the wire is as close as practicable to the support 15 in order that the feeding pressure thereof is utilized optimally, without the hazard of deforming the wires or detracting from the uniform winding thereof on the support.

It will have become apparent that the method and apparatus herein disclosed avoids any touching of wire with the fingers. It has been found that perspiration or soil which would otherwise be deposited on the wires can, in the case of high precision temperature-sensing elements, seriously detract from accuracy. In accordance with prior practice the far end of the winding was retained by attaching a length 91 of the same, e.g. platinum (FIG. 10) to the loop 92 and wrapping the same around the support several times to serve as an anchor. Such practice was unreliable and wasteful in terms of the excess platinum wire. The present disclosure provides for a pin 94 (FIG. 9) to be embedded in the support in a position close to the last turn so that the loop 30 may be held thereon. This pin is desirably installed when the support is still in the chuck. In this way, not only is the end of the coil reliably secured but wasteful consumption of costly wire is avoided.

The next step is to fix the turns of the winding against longitudinal slippage. Referring to FIG. 11, heat is applied to soften the glass to the point where the wire will become integrated with the support by fusion. The result is to cause the wires 22 to sink partially into the support and the glass to rise around the wires by capillary action to provide a unified structure.

Following this step the desired resistance of the coil is determined by employing any suitable instrument and the two wires 22 are welded together at the point thus ascertained, the short length of the wires beyond the weld and extending to the pin 94 becomes mere surplusage. However since the ultimate length of wire can be pre-determined within close limits, especially in the case of production runs, this surplusage can be readily minimized. Any excess length of the support 15 then remaining is cut off.

The component constituted as aforesaid, indicated at 101 in FIG. 12, is then positioned within a section of glass tubing 102 and, while rotating this sub-assembly, heat is applied over the coextensive region of the parts 101 and 102 and for some short distance at each end to soften the tubing, whereafterthe end portions 106 and 107 are grasped and longitudinal traction is applied. The end result is shown in FIG. 13 wherein the tubing 102 is constricted into embracing relation with the component, the wall thereof having been rendered sufficiently plastic to flow around, and incorporate itself with the wires 22-22 (FIG. 14). Thus the winding is fully protected on all sides.

Next, the tubing 102 is cut off at the lines XX and Y-Y in planes so selected that the remnants 110 and 1 l l are sufficient, when rendered plastic, to be formed around the ends of the support 15 which are also heated to the stage where the adjoining surfaces will fuse. The completed device, with the terminal leads protruding, then appears as in FIG. 15.

We claim:

1. In apparatus for winding comprising: a support, means to rotate said support to wind wire thereon, means to supply wire to said support, said wire having a leading end adapted for connection to said support and a trailing end and tension-applying means associated with the trailing end, the improvement which comprises: a rigid device interposed between the tensionapplying means and trailing end of the wire, said device having means to connect the tension-applying means at one side thereof and means to connect the wire at the other side thereof and bias means connected to said device to restrain the same from rotating about the axis of the wire whereby twisting of the wire is precluded as the same is fed to winding position.

2. The combination in accordance with claim 1 wherein said device comprises a frame essentially of U- shape, the legs whereof are the points of connection of the tension-applying means and the wire, and the bias means is attached to the bight of the frame.

3. An adjunct for maintaining uniform pitch of the turns of a coil composed of at least two wires as the same are wound concurrently on a support in intercalated relation, comprising a sup} ort, means to rotate said support to wind said wires t ereon, means to supply wire to said support, said wireseach having a leading end adapted for connection to said support and a trailing end and means to apply tension to the wires during winding, said adjunct comprising a hook-shaped member having a bight and a plurality of legs, a leg being positioned intermediate each pair of wires to be tangent thereto and to space the same and the bight resting on one of the wires, the dimension of said one leg at the points of contact with the wires being the pitch distance less the sum of the radii of the wires, and bias means secured to at least one of the legs to maintain said one leg in operative position. 

1. In apparatus for winding comprising: a support, means to rotate said support to wind wire thereon, means to supply wire to said support, said wire having a leading end adapted for connection to said support and a trailing end and tensionapplying means associated with the trailing end, the improvement which comprises: a rigid device interposed between the tensionapplying means and trailing end of the wire, said device having means to connect the tension-applying means at one side thereof and means to connect the wire at the other side thereof and bias means connected to said device to restrain the same from rotating about the axis of the wire whereby twisting of the wire is precluded as the same is fed to winding position.
 2. The combination in accordance with claim 1 wherein said device comprises a frame essentially of U-shape, the legs whereof are the points of connection of the tension-applying means and the wire, and the bias means is attached to the bight of the frame.
 3. An adjunct for maintaining uniform pitch of the turns of a coil composed of at least two wires as the same are wound concurrently on a support in intercalated relation, comprising a support, means to rotate said support to wind said wires thereon, means to supply wire to said support, said wires each having a leading end adapted for connection to said support and a trailing end and means to apply tension to the wires during winding, said adjunct comprising a hook-shaped member having a bight and a plurality of legs, a leg being positioned intermediate each pair of wires to be tangent thereto and to space the same and the bight resting on one of The wires, the dimension of said one leg at the points of contact with the wires being the pitch distance less the sum of the radii of the wires, and bias means secured to at least one of the legs to maintain said one leg in operative position. 